1. Field of the Invention
The present invention relates to the field of content protection. More specifically, the present invention addresses the provision of protection to digital video content to facilitate their secure transmission from a video source device to a video sink device.
2. Background Information
In general, entertainment, education, art, and so forth (hereinafter collectively referred to as xe2x80x9ccontentxe2x80x9d) packaged in digital form offer higher audio and video quality than their analog counterparts. However, content producers, especially those in the entertainment industry, are still reluctant in totally embracing the digital form. The primary reason being digital contents are particularly vulnerable to pirating. As unlike the analog form, where some amount quality degradation generally occurs with each copying, a pirated copy of digital content is virtually as good as the xe2x80x9cgold masterxe2x80x9d. As a result, much efforts have been spent by the industry in developing and adopting techniques to provide protection to the distribution and rendering of digital content.
Historically, the communication interface between a video source device (such as a personal computer) and a video sink device (such as a monitor) is an analog interface. Thus, very little focus has been given to providing protection for the transmission between the source and sink devices. With advances in integrated circuit and other related technologies, a new type of digital interface between video source and sink devices is emerging. The availability of this type of new digital interface presents yet another new challenge to protecting digital video content. While in general, there is a large body of cipher technology known, the operating characteristics such as the volume of the data, its streaming nature, the bit rate and so forth, as well as the location of intelligence, typically in the source device and not the sink device, present a unique set of challenges, requiring a new and novel solution.
A session key is generated by a video source device for each transmission session wherein a multi-frame video content is to be transmitted to a video sink device. The video source device in turn uses at least the session key to generate a successive number of frame keys to facilitate ciphering of corresponding frames of the multi-frame video content for transmission to the video sink device.